1. Field of the Invention
The present invention generally relates to an apparatus for transporting a tubular handling apparatus. Particularly, the present invention relates an apparatus for reducing a load on a frame for transporting a tubular handling apparatus. More particularly still, the present invention relates to a support frame adapted for use with a power frame for transporting a tubular handling apparatus.
2. Description of the Related Art
In the construction of oil or gas wells it is usually necessary to construct long drill pipes. Due to the length of these pipes, sections or stands of pipe are progressively added to the pipe string as it is lowered into the well from a drilling platform. In particular, when it is desired to add a section or stand of pipe, the pipe string is usually restrained from falling into the well by applying the slips of a spider located in the floor of the drilling platform. The new section or stand of pipe is then moved from a rack to the well center above the spider. The threaded pin of the section or stand of pipe to be connected is then located over the threaded box of the pipe string in the well and the connection is made up by rotation therebetween. Thereafter, the newly extended pipe string is released from the spider. The whole pipe string is then lowered until the top of the pipe section is adjacent the spider whereupon the slips of the spider are re-applied to maintain the pipe string in the wellbore.
It is common practice to use a tong assembly apply a predetermined torque to the connection in order to make this connection. The tong assembly is typically located on the platform, either on rails, or hung from a derrick on a chain. In order to make up or break out a threaded connection, the tong assembly has a two tong arrangement. An active (or wrenching) tong supplies torque to the section of pipe above the threaded connection, while a passive (or back up) tong supplies a reaction torque below the threaded connection. Particularly, the back up tong clamps the pipe below the threaded connection, and prevents it from rotating. The clamping of the pipe string may be performed mechanically, hydraulically, or pneumatically. The wrenching tong clamps the upper part of the connection and is driven so that it supplies torque for a limited angle.
This power tong arrangement may also be used to make up connections between other tubulars, for example casing and tubing. Although the arrangement remains the same, the tongs may be replaced or changed for different sized tubulars. This is because tongs are typically adapted for use within a range of tubular sizes. Therefore, tongs are generally changed as the tubular sizes vary.
Conventionally, power tongs including the two tong arrangement described above and other commercially available tongs are suspended by chains from a crane or other support. However, the chains may get in the way of other equipment. For example, the chains may block access to a drill pipe spinner which is used to partially make up a threaded connection before a final tightening of the connection by the wrenching and backup tongs.
There is a need, therefore, for an apparatus for providing support for a tong assembly that reduces equipment interferences during operation. There is also a need for an apparatus for reducing a load on a frame for transporting a tubular handling apparatus. There is a further need for an adapter frame that may be used with a power frame for supporting a tong assembly.